Effect of the phase composition of iron oxide nanorods on SO2 gas sensing performance

• Published in: Materials research bulletin 2021-02, Vol.134, p.111087, Article 111087
• Main Authors: Nguyen, Thanh Vinh, Luong, Ngoc Anh, Nguyen, Van Toan, Pham, Anh Tuan, Le, Anh Tuan, To, Thanh Loan, Nguyen, Van Quy
• Format: Article
• Language: English
• Subjects: Gas sensor; Iron oxide; Nanorods; QCM; SO2
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2020.111087

[Display omitted] •The FeOOH, γ-Fe2O3, and α-Fe2O3 nanorods with numerous functional groups of OH were prepared by a simplistic method.•The effect of phase compositions of iron oxide nanorods on sensing properties was also discussed.•Mass-type sensor bases on γ-Fe2O3 exposes the highest response to SO2.•This study has opened up a new sighting of the iron oxide in a sensing application. α-FeOOH nanorods were synthesized by a facile precipitation method. γ-Fe2O3 and α-Fe2O3 nanorods were then obtained by calcining for 6 h at 200 and 600 °C in ambient air, respectively. A mass-type sensor was developed based on the different iron oxide phase compositions of α-FeOOH, γ-Fe2O3 and α-Fe2O3 coating a quartz crystal microbalance (QCM). The gas sensing properties of three as-prepared sensors were systematically examined for detecting sulphur dioxide gas (SO2) at room temperature. The effect of phase composition of iron oxide nanorods on sensing properties was also discussed. Although as-prepared iron oxides have a similar morphologic structure, the sensor based on γ-Fe2O3 exposes the highest response to SO2. The sensing results show that the γ-Fe2O3 coated QCM sensors had an extremely good performance for SO2 gas in the 2.5–20 ppm range at room temperature.